This site is supported by donations to The OEIS Foundation.



Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A002381 Numbers of the form (p^2 - 1)/120 where p is 1 or prime.
(Formerly M2614 N1034)

%I M2614 N1034

%S 0,1,3,7,8,14,29,31,42,52,66,85,99,143,161,185,190,267,273,304,330,

%T 371,437,476,484,525,603,612,658,806,913,1015,1074,1197,1261,1340,

%U 1394,1463,1477,1548,1606,1680,1771,1912,2009,2075,2159,2262,2439,2698,2717

%N Numbers of the form (p^2 - 1)/120 where p is 1 or prime.

%C For n>1, primes p corresponding to a(n) are in A038872(n) = A045468(n-1) = A141158(n). - _Ray Chandler_, Jul 29 2019

%D H. Gupta, On a conjecture of Chowla, Proc. Indian Acad. Sci., 5A (1937), 381-384.

%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H Ray Chandler, <a href="/A002381/b002381.txt">Table of n, a(n) for n = 1..10000</a>

%H H. Gupta, <a href="/A002381/a002381.pdf">On a conjecture of Chowla</a>, Proc. Indian Acad. Sci., 5A (1937), 381-384. [Annotated scanned copy]

%o (PARI) j=[]; for(n=0,150,x=prime(n)^2-1; if(Mod(x,120)==0,j=concat(j,(x/120)))); j

%Y Cf. A002382, A002855, A038872, A045468, A141158, subsequence of A093722.

%K nonn

%O 1,3

%A _N. J. A. Sloane_.

%E More terms from _Jason Earls_, Jul 29 2001

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 10 00:54 EST 2019. Contains 329885 sequences. (Running on oeis4.)